1. Field of the Invention
The present invention relates to an open end wrench and, more particularly, to an improved high torque open end wrench.
2. Description of the Related Art
An open end wrench typically has two jaws that are spaced apart to engage the flats of a fastener head and is generally used to turn and control the rotation of bolts, nuts and other fasteners. An open end wrench may be formed in a double open end, combination box end or other suitable configuration and can access fasteners under certain limited conditions where a closed end or box wrench is impractical. Open end wrenches, however, can be weaker than a box wrench due to the unsupported nature of a cantilever jaw. Reaction forces exerted on the jaws by the fastener transverse to either or both of the wrench's jaw faces cause a bending moment about the base of the jaws relative to the head. These reaction forces cause the jaws to expand as increased torque is exerted on the fastener.
There have been numerous attempts to increase the strength and torque capacity of open end wrenches, including the use of sharp teeth or serrations on the jaws or inclined and arcuate driving surfaces.